1. Field of the Invention
This invention relates to a method and an apparatus for continuously recording audio visual data on a plurality of recording mediums. In addition, this invention relates to a method and an apparatus for continuously reproducing audio visual data from a plurality of recording mediums.
2. Description of the Related Art
Some video data recording and reproducing apparatuses or recordable video players use recordable DVDs (Digital Versatile Discs) having a diameter of 12 cm. Such DVDs are of a single-layer type and a multi-layer type. A single-layer DVD has only one recording layer. A multi-layer DVD has a plurality of recording layers. Generally, one recording layer in a DVD is about 4.7 GB in recording capacity.
During an SP (Standard Play) mode of recording operation of a recordable video player, audio visual data representing a movie or a television program having a play time of up to about 2 hours can be recorded on one recording layer in a DVD. During the SP mode of recording operation, audio visual data representing a movie or a television program having a play time longer than 2 hours can be recorded on two or more single-layer DVDs.
For example, a first portion of audio visual data representing a movie longer than 2 hours is recorded on a first DVD while a second portion thereof (the rest thereof) is recorded on a second DVD. In this case, information for management of the first portion of the audio visual data is also recorded on the first DVD. Similarly, information for management of the second portion of the audio visual data is also recorded on the second DVD. The information for management of the first portion of the audio visual data is absent from the second DVD while the information for management of the second portion of the audio visual data is absent from the first DVD. Therefore, the information for management of the first portion of the audio visual data can not be obtained by access to the second DVD. The information for management of the second portion of the audio visual data can not be obtained by access to the first DVD. Thus, it tends to be difficult to smoothly and harmoniously manage the whole of the audio visual data recorded on the first and second DVDs.
Japanese patent application publication number 2002-157824 discloses data recording apparatus including a removable optical disc and a large-capacity buffer. The apparatus records a data stream on the optical disc while checking whether or not the remaining usable capacity of the optical disc decreases to a prescribed value in order to decide whether or not the optical disc is substantially fully occupied by recorded data. When the remaining usable capacity of the optical disc decreases to the prescribed value, the apparatus halts the recording of the data stream on the optical disc. As a result, a first portion of the data stream is stored in the optical disc while a second portion thereof which immediately follows the first portion is not. The apparatus stores the second portion of the data stream into the buffer. The apparatus decides whether or not the optical disc is replaced by new one. After the optical disc has been replaced by new one, the apparatus transfers the second portion of the data stream from the buffer onto the new optical disc through processes including a data recording process.
In the apparatus of Japanese application 2002-157824, the data stream may always be written into the buffer before being transferred therefrom onto the optical discs. The apparatus may be equipped with a disc changer for implementing optical-disc replacement.
Japanese patent application publication number 2004-127471 equivalent to United States patent application publication number US 2005/0008346 A1 discloses a data recording apparatus including a disc drive mechanism and a disc changing mechanism. The disc changing mechanism contains a plurality of optical discs, and serves to select one from the optical discs and feed the selected optical disc to the disc drive mechanism. During a continuous recording mode of operation, the apparatus divides a data stream indicative of a television program into portions and records the division-result portions on optical discs respectively.
The apparatus in Japanese application 2004-127471 further includes a recording buffer. During the recording of a data stream on a first optical disc, the apparatus checks whether or not the remaining usable capacity of the first optical disc decreases to a prescribed level or whether or not the remaining recordable time regarding the first optical disc decreases to a prescribed value. When the remaining usable capacity decreases to the prescribed level or when the remaining recordable time decreases to the prescribed value, the apparatus halts the recording of the data stream on the first optical disc. Then, the apparatus replaces the first optical disc with a second optical disc. The apparatus loads the recording buffer with a portion of the data stream which should be recorded during the optical-disc replacement. The apparatus checks whether or not the optical-disc replacement is completed. After the optical-disc replacement is completed, the apparatus reads the portion of the data stream from the recording buffer and then records the read portion on the second optical disc.
In the apparatus of Japanese application 2004-127471, ones can be designated and selected among the optical discs in the disc changing mechanism as objects to be loaded with a data stream indicative of a television program. The designated optical discs are referred to as combination discs. The apparatus generates combination designating information including information for identifying optical discs labeled as combination discs, and information for specifying a recording order in which portions of a data stream should be recorded on the combination discs respectively. The apparatus records such combination designating information on each optical disc as a part of disc management information used for the management of the recording and reproduction of data on and from the optical disc. The disc management information also includes information related to a television program at least partially recorded on the optical disc such as information representing the title of the television program and the date of the recording of the television program.